aluminum

Aluminum, or aluminium in most of the world, is a chemical element with symbol Al and atomic number 13. It is the third most abundant element in Earth's crust and accounts for about 8% of its weight. It occurs primarily in the ore bauxite and is widely produced and used because of its low density and high strength-to-weight ratio.

In its pure form aluminum is a soft, silvery-white metal that is lightweight and highly ductile. It resists corrosion thanks to a thin, naturally forming aluminum oxide layer. It conducts heat and electricity well and forms strong, lightweight alloys with magnesium, silicon, and other elements.

Production involves extracting alumina from bauxite by the Bayer process, then reducing alumina to metal by the Hall–Héroult electrolysis process. The operation is energy intensive, and electricity costs shape the global industry. Aluminum production is concentrated in a few countries, with recycling playing a significant role in supply.

Recycling aluminum is common and energy-efficient; recycled aluminum saves a large fraction of the energy required for primary production and supports a substantial portion of the supply, with beverage cans and packaging among the most recycled streams.

Historically, aluminum was first produced in 1825 by Hans Christian Ørsted, with further refinements by Friedrich Wöhler; commercial production began in 1886 after Hall and Heroult developed the electrolysis method. The spelling aluminium is standard in many countries; aluminum is common in the United States.

Uses include transportation (aircraft and automobiles), construction (windows, facades, and siding), packaging (foil and cans), electrical components, and a wide range of consumer goods.